This study aims to investigate the effects and mechanisms of heat stress (HS) on the physiological functions of the liver in primiparous sows during early pregnancy.In the experimental design, we exposed early pregnant sows to HS (high temperature and humidity environment) and TN (normal environment) conditions. Through blood gas analysis, endocrine index detection, biochemical detection, and histological immunofluorescence analysis, we evaluated the systemic physiological responses and liver damage in sows under HS.Additionally, the study carried out preliminary transcriptomics, proteomics, and metabolomics analyses of the liver to reveal the molecular mechanisms underlying liver dysfunction caused by HS.